Adolescents are getting clear messages from their teachers, families, peers and the media concerning the harms of cigarette smoking, but receive conflicting or minimal information about the potential and real harms of marijuana and e-cigarettes, the study showed.

“Kids were really good at describing the harmful things that happen with cigarette smoking, but when we asked about other products, there was a lot of confusion.”

“We’re good at delivering messaging that cigarettes are harmful, but we need to do a better job with other products that teens may smoke,” remarked Bonnie Halpern-Felsher, PhD, professor of pediatrics in adolescent medicine and the study’s senior author. “We don’t want the message kids get to be ‘cigarettes are bad, so everything else might be OK.'”

The two researchers compared teens’ knowledge of cigarettes, e-cigarettes and marijuana because they kept hearing from parents, teachers, and youth that anti-smoking campaigns needed to talk about more than just regular cigarettes.

The need is confirmed by other research.

A recent study from the Centers for Disease Control shows that middle- and high-school students’ use of e-cigarettes tripled from 2013 to 2014, overtaking cigarettes as the most common tobacco product in this age group.

Halpern-Felsher and Roditis study involved 24 high school age adolescents. The students took part in small-group discussions about their perceptions of the risks and benefits of conventional cigarettes, e-cigarettes and marijuana.

They also talked about how they learned of these products. The researchers analyzed the trends that emerged in the discussions.

It was found that students saw little or no benefit, as well as several detrimental effects, of smoking conventional cigarettes, such as yellowed teeth, bad breath and long-term disease risk.

They also said their social norms often discouraged smoking conventional cigarettes. For instance, even smoking marijuana rolled in paper was considered weird because it looks like a cigarette.

But students did see getting high as a benefit to smoking marijuana, perceiving it as safer and less addictive than tobacco. They were unsure whether marijuana posed health risks, and also described being under peer pressure to smoke marijuana.

With respect to e-cigarettes, students perceived some benefits, including thinking e-cigarettes looked good, but were unsure of the risks.